1. Field of the Invention
The invention relates generally to thermostats and more particularly to a thermostat having a signal transceiver for two-way communication with an energy provider.
2. Description of the Prior Art
Thermostats have been used for many years for enabling a user to regulate the temperature of a space by setting a temperature setpoint. When the temperature within the space goes outside the temperature setpoint, the thermostat sends a signal to operate a cooling or heating device. The cooling or heating device converts energy, typically either electricity or gas, to cool or heat the space to bring the temperature to the setpoint.
Recently thermostat systems have been developed that include a microprocessor based controller and a pager receiver for receiving signal information or commands in the form of a paging signal from an energy provider such as a utility company. The energy provider issues information for the current price of energy, for example low, medium, high, or critical, in the paging signal. The user enters into the thermostat the temperature setpoints and the costs of energy that are acceptable to him for maintaining temperature at the temperature setpoints. For example, a user having a heater may enter a temperature setpoint of 70.degree. F. for a low energy cost, 65.degree. F. for a medium energy cost, 60.degree. F. for a high energy cost, and 50.degree. F. for a critical energy cost. Such system enables the user to manage his energy cost while enabling the energy provider to smooth energy demand peaks and to shed load during an energy crises situation. However, a limitation of such system is that it does not provide information to the energy provider for predicting the effect of a change in the price of energy upon the demand for energy or for verifying that an action effecting the demand has taken place.